miri: shim CCRandomGenerateBytes

Author: joboet

src/tools/miri/src/shims/unix/macos/foreign_items.rs

@@ -78,6 +78,16 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 this.write_pointer(environ, dest)?;
             }
 
+            // Random data generation
+            "CCRandomGenerateBytes" => {
+                let [bytes, count] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
+                let bytes = this.read_pointer(bytes)?;
+                let count = this.read_target_usize(count)?;
+                let success = this.eval_libc_i32("kCCSuccess");
+                this.gen_random(bytes, count)?;
+                this.write_int(success, dest)?;
+            }
+
             // Time related shims
             "mach_absolute_time" => {
                 let [] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;

src/tools/miri/tests/pass-dep/libc/ccrandomgeneratebytes_apple.rs

@@ -0,0 +1,7 @@
+//@only-target-apple: this directly tests apple-only functions
+
+fn main() {
+    let mut bytes = [0u8; 24];
+    let ret = unsafe { libc::CCRandomGenerateBytes(bytes.as_mut_ptr().cast(), bytes.len()) };
+    assert_eq!(ret, libc::kCCSuccess);
+}